This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Arsenic in drinking water is affecting upwards of 30 million people in Bangladesh and surrounding areas. Our previous x-ray absorption spectroscopy studies revealed an intimate link between the toxicities of arsenic and selenium ? a molecule with a single atom of each provides a route to mutual detoxification. This and other evidence strongly indicates that the Bangladeshi arsenicosis actually causes people to become selenium deficient, a hypothesis currently under test by clinical trial of selenium supplements in Bangladesh. If the selenium deficiency hypothesis is proven, then a diet rich in selenium is essential to counter the arsenicosis and a staple food enriched in selenium would be the best way of providing this essential micronutrient. To this end we are investigating selenium enrichment of lentils. Preliminary results show that lentils readily take up and store selenium. Bangladesh imports lentils from several countries including Canada, where the lentil crop grows in selenium-rich soils of southern Saskatchewan. Selenium is essential for all humans, and such selenium-rich lentils are also a potential health food for North American markets. To more fully assess the nutritional benefit of the lentils we need to measure the selenium chemical form. We plan a series of experiments using x-ray absorption spectroscopy (XAS) to elucidate the chemical form and XAS imaging to visualize localization of selenium forms and other micronutrients in plant and seed. We will study laboratory grown plants as well as field-harvested seeds and will follow the seed through processing from plant to dinner plate. Determining the selenium molecular form in lentils will provide important information regarding the benefits of the lentils to human health, as well as fundamental information regarding the physiology of plant selenium uptake. If successful, selenium rich lentils could provide a practical solution to a health problem affecting tens of millions.